Flex circuit and surface mounted electrode catheter

Abstract

To provide a medical system.SOLUTION: In one embodiment, a medical system includes a catheter to be inserted into a body part, the catheter including an elongated deflectable element including a distal end, a proximal coupler connected to the distal end, an expandable assembly comprising flexible polymer circuit strips, each flexible polymer circuit strip including strip electrodes and a respective contact pad disposed thereon, the flexible polymer circuit strips having respective proximal ends connected to, and disposed circumferentially around, the proximal coupler, and surface mountable electrodes electrically connected to respective ones of the flexible polymer circuit strips, where each surface mountable electrode is electrically connected to the respective contact pad of a respective one of the flexible polymer circuit strips using at least one electrically conductive retainer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to medical devices, particularly but not exclusively to catheters having electrodes. [Background technology]

[0002] A wide variety of medical procedures involve the placement of probes, such as catheters, within a patient's body. Position sensing systems have been developed to track such probes. Magnetic position sensing is one method known in the art. In magnetic position sensing, magnetic field generators are typically placed at known locations external to the patient. A magnetic field sensor in the distal end of the probe generates electrical signals in response to these magnetic fields, and these signals are processed to determine the coordinate position of the distal end of the probe. These methods and systems are described in U.S. Patent Nos. 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, WO 1996 / 005768, and U.S. Patent Application Publication Nos. 2002 / 0065455, 2003 / 0120150, and 2004 / 0068178. Position may also be tracked using impedance or current-based systems.

[0003] One medical procedure in which these types of probes or catheters have proven extremely useful is in the treatment of cardiac arrhythmias, which, and atrial fibrillation in particular, continue to be a common and dangerous condition, especially in the aging population.

[0004] Diagnosis and treatment of cardiac arrhythmias involve mapping the electrical properties of cardiac tissue, particularly the endocardium and cardiac volumes, and selectively ablating cardiac tissue through the application of energy. Such ablation can stop or modify the propagation of unwanted electrical signals from one part of the heart to another. The ablation process disrupts unwanted electrical pathways by creating non-conductive lesions. Various energy delivery modalities have been previously disclosed for creating lesions, including the use of microwave, laser, and more generally radiofrequency energy to create conduction blocks along cardiac tissue walls. In a two-step mapping-then-ablation procedure, a catheter containing one or more electrical sensors is typically advanced into the heart to obtain data at multiple points to detect and measure electrical activity at each point within the heart. These data are then used to select a target region of the endocardium for this ablation.

[0005] Electrode catheters have been commonly used in medical practice for many years. They are used to stimulate and map electrical activity within the heart and to ablate sites of abnormal electrical activity. In use, an electrode catheter is inserted into a major vein or artery, such as the femoral vein, and then guided into the heart chamber of interest. A typical ablation procedure involves inserting a catheter with one or more electrodes at its distal end into a heart chamber. A reference electrode is typically taped to the patient's skin or may be provided by a second catheter placed in or near the heart. Radio frequency (RF) current is applied between the tip electrode of the ablation catheter and the reference electrode, and current flows between the electrodes, i.e., through the medium between the blood and tissue. The distribution of the current depends on the amount of electrode surface in contact with the tissue compared to blood, which has a higher electrical conductivity than tissue. Tissue heating occurs due to the electrical resistance of the tissue. Sufficient tissue heating can cause cell destruction in the cardiac tissue, resulting in the formation of lesions in the non-conductive cardiac tissue.

[0006] U.S. Patent Publication No. 2014 / 0276733 to VanScoy et al. describes an ablation catheter including an elongated body having a proximal end and a distal end. At least one ablation element is disposed on the body between the proximal end and the distal end and configured to ablate renal tissue to control hypertension. At least one localization sensor is disposed on the body and configured to interact with a magnetic field. The at least one localization sensor aids in determining an appropriate target tissue for ablation.

[0007] U.S. Patent Publication No. 2008 / 0125772 to Stone et al. describes a catheter and catheter system that uses tailored energy for the remodeling and / or removal of targeted material along a body lumen, often atherosclerotic material in a patient's blood vessels. An elongated, flexible catheter body having a radially expandable structure may have multiple electrodes or other electrosurgical energy delivery surfaces to radially engage the atherosclerotic material when the structure expands. The atherosclerotic material detector system can optionally use impedance monitoring to measure and / or characterize the atherosclerotic material and its location.

[0008] U.S. Patent Publication No. 2011 / 0137298 to Nguyen et al. describes an ablation device comprising an ultrasonic transducer including a piezoelectric element having a cylindrical shape, a plurality of external electrodes disposed on the outer surface of the piezoelectric element, and at least one internal electrode disposed on the inner surface of the piezoelectric element. The internal electrode provides corresponding internal electrode portions disposed on opposite sides of the piezoelectric element from the external electrodes, and the external electrode and the at least one internal electrode are energized to apply an electric field across the piezoelectric element. The ultrasonic ablation zones of the external electrodes are distributed in a staggered configuration to span one or more open arc segments about a longitudinal axis, and the ultrasonic ablation zones of all the external electrodes projected longitudinally on any transverse plane perpendicular to the longitudinal axis span a substantially closed loop about the longitudinal axis. Summary of the Invention [Means for solving the problem]

[0009] According to yet another embodiment of the present disclosure, there is provided a medical system including a catheter configured to be inserted into a body part of a living subject, the catheter including an elongated, deflectable element including a distal end, a proximal coupler connected to the distal end, an expandable assembly including a plurality of flexible polymer circuit strips, each flexible polymer circuit strip including a plurality of strip electrodes and respective contact pads disposed thereon, the flexible polymer circuit strips connected to the proximal coupler and having respective proximal ends disposed circumferentially around the proximal coupler, and a plurality of surface-mountable electrodes electrically connected to respective ones of the flexible polymer circuit strips, each surface-mountable electrode electrically connected to a respective contact pad on a respective one of the flexible polymer circuit strips using at least one conductive retainer.

[0010] Furthermore, according to an embodiment of the present disclosure, each surface-mountable electrode extends around a respective flexible polymer circuit strip.

[0011] Still further, in accordance with an embodiment of the present disclosure, the system includes an ablation power generator connected to the catheter and configured to apply an electrical signal to at least one of the surface-mountable electrodes to ablate tissue at the body site; and a mapping module configured to receive the electrical signal from one of the strip electrodes of the flexible polymer circuit strip and generate an electro-anatomical map in response to the received electrical signal.

[0012] Additionally, according to embodiments of the present disclosure, the ablation power generator is configured to apply an electrical signal between ones of the surface-mountable electrodes.

[0013] Further, according to an embodiment of the present disclosure, a catheter includes a distal connector, flexible polymer circuit strips connected to the distal connector and having respective distal ends circumferentially disposed around the distal connector, the catheter having a distal tip, and the catheter including a distal electrode disposed at the distal tip of the catheter between the distal ends of the flexible polymer circuit strips.

[0014] Furthermore, according to an embodiment of the present disclosure, the system further includes an ablation power generator connected to the catheter and configured to apply an electrical signal between at least one of the surface-mountable electrodes and the distal electrode to ablate tissue at the body site, and a mapping module configured to receive electrical signals from ones of the strip electrodes of the flexible polymer circuit strip and generate an electro-anatomical map in response to the received electrical signals.

[0015] Still further, according to an embodiment of the present disclosure, each surface-mountable electrode includes a proximal end and a distal end, the proximal end and the distal end of each surface-mountable electrode being electrically connected to respective contact pads of a respective flexible polymer circuit strip using two respective conductive retainers.

[0016] Additionally, according to embodiments of the present disclosure, the proximal and distal ends of each surface-mountable electrode are connected to a respective flexible polymer circuit strip using an adhesive.

[0017] Further, according to an embodiment of the present disclosure, each flexible polymer strip includes multiple layers, a first layer of the multiple layers including the circuit traces, and a second layer of the multiple layers including the strip electrodes and respective contact pads.

[0018] Further, according to an embodiment of the present disclosure, a catheter includes a pusher including a distal portion and configured to be advanced and retracted through a deflectable element, the catheter including a distal link connected to the distal portion of the pusher, flexible polymer circuit strips disposed circumferentially around the distal portion of the pusher, the flexible polymer circuit strips having respective distal ends connected to the distal links, the strips configured to arc radially outward when the pusher is retracted to expand the expandable assembly from a collapsed configuration to an expanded configuration.

[0019] Still further, according to embodiments of the present disclosure, the surface-mountable electrodes are connected to respective ones of the flexible polymer circuit strips in a staggered arrangement with every other surface-mountable electrode disposed more proximally than the other surface-mountable electrodes.

[0020] Additionally, according to an embodiment of the present disclosure, each of the flexible polymer circuit strips has a respective outer surface, and each of the surface-mountable electrodes includes a conductive material biased toward the respective outer surface of each of the flexible polymer circuit strips.

[0021] According to another embodiment of the present disclosure, there is also provided a method of manufacturing a catheter, the method including: providing a catheter including an elongated, deflectable element; a proximal coupler connected to a distal end of the elongated, deflectable element; and an expandable assembly including a plurality of flexible polymer circuit strips, each including a plurality of strip electrodes and respective contact pads disposed thereon, the flexible polymer circuit strips connected to the proximal coupler and having respective proximal ends circumferentially disposed around the proximal coupler; and electrically connecting a plurality of surface-mountable electrodes to respective ones of the flexible polymer circuit strips, such that each surface-mountable electrode is electrically connected to a respective contact pad on each one of the flexible polymer circuit strips using at least one conductive retainer.

[0022] Furthermore, according to an embodiment of the present disclosure, each surface-mountable electrode extends around a respective flexible polymer circuit strip.

[0023] Further, according to an embodiment of the present disclosure, a catheter includes a distal connector, flexible polymer circuit strips connected to the distal connector and having respective distal ends circumferentially disposed around the distal connector, the catheter having a distal tip, and the catheter including a distal electrode disposed at the distal tip of the catheter between the distal ends of the flexible polymer circuit strips.

[0024] Additionally, according to an embodiment of the present disclosure, electrically connecting includes electrically connecting the proximal and distal ends of each surface-mountable electrode to respective contact pads of each flexible polymer circuit strip using two respective conductive retainers.

[0025] Still further, in accordance with an embodiment of the present disclosure, the method includes connecting the proximal and distal ends of each surface-mountable electrode to a respective flexible polymer circuit strip using an adhesive.

[0026] Additionally, according to an embodiment of the present disclosure, the method further includes forming each flexible polymer circuit strip from a plurality of layers, a first layer of the plurality of layers including the circuit traces and a second layer of the plurality of layers including the strip electrodes and respective contact pads.

[0027] Further, according to an embodiment of the present disclosure, a catheter includes a pusher including a distal portion and configured to be advanced and retracted through a deflectable element, the catheter including a distal link connected to the distal portion of the pusher, flexible polymer circuit strips disposed circumferentially around the distal portion of the pusher, the flexible polymer circuit strips having respective distal ends connected to the distal links, the strips configured to arc radially outward when the pusher is retracted to expand the expandable assembly from a collapsed configuration to an expanded configuration.

[0028] Further, according to an embodiment of the present disclosure, the method includes connecting the surface-mountable electrodes to respective ones of the flexible polymer circuit strips in a staggered arrangement with every other one of the surface-mountable electrodes disposed more proximally than the other one of the surface-mountable electrodes.

[0029] According to yet another embodiment of the present disclosure, there is also provided an electrophysiology flexible circuit device including: an elastic substrate extending from a first substrate end to a second substrate end; a flexible circuit strip extending from the first strip end to the second strip end, the flexible circuit strip coupled to the elastic substrate and having conductive contact pads disposed on the flexible circuit strip; a plurality of recording electrodes disposed on the flexible circuit strip, each recording electrode configured to record electrical signals from biological tissue; at least one fiber disposed between the elastic substrate and the flexible circuit strip; and an ablation electrode having a hollow portion extending through the ablation electrode and allowing the flexible circuit strip, the at least one fiber, and the elastic substrate to extend through the hollow portion, the ablation electrode having at least one conductive retainer electrically connecting the ablation electrode to the conductive contact pads.

[0030] Still further, according to embodiments of the present disclosure, the device includes an adhesive that attaches the ablation electrodes to any one or more of the flexible circuit strip, the elastic substrate, and the conductive contact pads.

[0031] Additionally, according to embodiments of the present disclosure, each of the recording electrodes includes a first exposed surface area and each ablation electrode includes a second exposed surface area that is at least three times the first exposed surface area.

[0032] Further, according to an embodiment of the present disclosure, the first strip end includes a hinge and a first portion, a second portion, and a third portion, the first portion having a first width that tapers to a second width, and the second portion tapers from the second width to a final width at the third portion of the first strip end.

[0033] Furthermore, according to an embodiment of the present disclosure, the at least one fiber comprises a yarn.

[0034] Still further, in accordance with an embodiment of the present disclosure, each recording electrode comprises a planar electrode.

[0035] Additionally, according to an embodiment of the present disclosure, the ablation electrode includes an elongated member having a semi-cylindrical cross-section. [Brief explanation of the drawings]

[0036] The present invention will be understood from the following detailed description taken in conjunction with the accompanying drawings. [Figure 1] 1 is a partially pictorial, partially block diagram of a medical system constructed and operative in accordance with an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic diagram of a catheter of the system of FIG. 1. [Figure 3] FIG. 3 is a partially exploded view of the catheter of FIG. 2. [Figure 4A] FIG. 3 is a schematic diagram of the distal end of the catheter of FIG. 2 without the distal electrode. [Figure 4B] FIG. 3 is a schematic diagram of the distal end of the flexible polymer circuit strip of the catheter of FIG. 2. [Figure 4C] FIG. 3 is a schematic diagram of the distal end of the flexible polymer circuit strip of the catheter of FIG. 2. [Figure 5] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 6] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 7A] 2A-2C are schematic diagrams showing the catheter of FIG. 1 in a deployed and collapsed configuration, respectively. [Figure 7B] 2A-2C are schematic diagrams showing the catheter of FIG. 1 in a deployed and collapsed configuration, respectively. [Figure 8] FIG. 3 is a schematic diagram of the flexible polymer circuit strip of the catheter of FIG. 2. [Figure 9] FIG. 3 is a schematic diagram of the flexible polymer circuit strip of the catheter of FIG. 2 showing the circuit traces. [Figure 10] FIG. 3 is a schematic diagram of the flexible polymer circuit strip of the catheter of FIG. 2 showing the circuit traces. [Figure 11]FIG. 9 is a schematic diagram of the flexible polymer circuit strip of FIG. 8 with surface-mountable electrodes attached. [Figure 12] FIG. 12 is a more detailed view of the surface-mountable electrode of FIG. [Figure 13] FIG. 13 is a cross-sectional view taken along line AA in FIG. 12. [Figure 14] FIG. 13 is a cross-sectional view taken along line BB in FIG. [Figure 15] 3 is a flow chart including steps in a method of manufacturing the catheter of FIG. 2. [Figure 16] FIG. 3 is a schematic diagram of a bias electrode for use in the catheter of FIG. 2. [Figure 17] FIG. 17 is a cross-sectional view of the bias electrode taken along line AA in FIG. 16. DETAILED DESCRIPTION OF THE INVENTION

[0037] Overview Diagnostic catheters, such as basket catheters, provide many electrodes for capturing electrical signals, such as electrical potentials, from tissues in a patient's body region. The electrical signals can then be analyzed to provide an indication of the medical condition of the body region. For example, the electrical signals can be used to provide an electroanatomical map. The medical condition of the body region may indicate that a portion of the tissue may require ablation (e.g., radiofrequency (RF) ablation or irreversible electroporation (IRE)) using a suitable catheter. While basket catheter electrodes may be suitable for diagnostic purposes, the electrodes and / or connections to the electrodes may be too small for use in ablation. This is particularly true for IRE, which uses high currents and requires a large electrode surface area to provide effective IRE ablation. Therefore, in such situations, the diagnostic basket catheter is removed from the patient, and a suitable ablation catheter is inserted into the patient's body region to perform the ablation. The use of two catheters may increase the length of the medical procedure, delaying the essential therapeutic procedure, and the time delay and use of two catheters may increase trauma to the patient.

[0038] Embodiments of the present invention solve the above problems by providing a basket catheter that includes both diagnostic and ablation electrodes, thereby providing a combined therapeutic and diagnostic catheter.

[0039] The basket catheter includes a distal expandable assembly made of flexible polymer circuit strips connected together proximally and distally to form a basket. Each strip includes a diagnostic electrode. Each strip also includes an ablation electrode connected to the strip. The ablation electrode of each strip may slide over the strip, may be wrapped around the strip, or may be formed from two sections connected together around the strip.

[0040] In some embodiments, the ablation electrodes are connected to the flexible polymer circuit strip in a staggered arrangement with alternating ablation electrodes disposed more proximally than the other to allow for compact storage of the expandable assembly during insertion and removal of the catheter into and from the patient.

[0041] In some embodiments, each strip includes contact pads generally formed in the same or similar manner as the diagnostic electrodes. In disclosed embodiments, the contact pads are larger than the diagnostic electrodes. The ablation electrodes are connected to their respective contact pads using a suitable bonding method, such as using solder, conductive epoxy, resistance welding, laser welding, or any other suitable method, to provide an electrical connection between each ablation electrode and its corresponding contact pad. The ablation electrodes may be connected using one or two bonding portions. The ablation electrodes are also referred to herein as surface-mountable electrodes. The diagnostic electrodes are also referred to herein as strip electrodes. Adhesives may also be used to connect the surface-mountable electrodes to the strips in addition to bonding.

[0042] In some embodiments, a mapping module executed by the processor receives electrical signals from at least some of the strip electrodes of the flexible polymer circuit strip and generates an electroanatomical map in response to the received electrical signals. An ablation power generator is connected to the catheter and applies electrical signals to one or more of the surface-mountable electrodes to ablate tissue at the body site (using RF or IRE ablation). In some embodiments, the ablation power generator applies electrical signals between at least some of the surface-mountable electrodes.

[0043] In some embodiments, the catheter may include an electrode, referred to herein as a distal electrode, located at the distal tip of the catheter between the distal ends of the strips. The distal electrode may be used for ablation. In some embodiments, an ablation power generator applies an electrical signal between one or more of the surface-mountable electrodes and the distal electrode to ablate tissue at the body site (using RF or IRE ablation).

[0044] In some embodiments, the ablation electrode is biased so that there is more material on the tissue-contacting side of the strip, thereby allowing the distal tip assembly to be folded into a small sheath. Another aspect of this electrode design ensures that the biasing (i.e., protrusion) is atraumatic and enhances ablation power on the tissue-contacting side. In some embodiments, atraumatic biasing is achieved by smoothing any sharp edges in the ablation electrode. Smoothing the sharp edges helps prevent any damage to the tissue or sheath and prevents high current densities that could result in arcing.

[0045] System Description Reference is now made to Figure 1, which is a partially pictorial, partially block diagram of a medical system 10 constructed and operative in accordance with an embodiment of the present invention. Medical system 10 includes a catheter 12 configured to be inserted into a body region 14 (e.g., a cardiac chamber) of a living subject.

[0046] Catheter 12 includes an elongated deflectable element 16 including a distal end 18. Elongated deflectable element 16 may have any suitable outer diameter and length, for example, the outer diameter may range from 1 mm to 4 mm and the length may range from 1 cm to 15 cm.

[0047] The catheter 12 also includes a proximal connector 20 connected to the distal end 18. The proximal connector 20 may be formed as an integral part of the deflectable element 16 or as a separate element and then connected to the distal end 18 using any suitable connection method, such as using an adhesive, e.g., epoxy. The catheter 12 also includes an expandable distal end assembly 22 including flexible circuit strips 24 (only some of which are labeled for simplicity). In some embodiments, the flexible circuit strips 24 are flexible polymer circuit strips. Each flexible polymer circuit strip 24 includes a plurality of strip electrodes 26 (e.g., mapping, recording, or diagnostic electrodes) (only some of which are labeled for simplicity) and respective conductive contact pads 28 disposed thereon. The contact pads 28 are mostly obscured in FIG. 1 and are more clearly shown in FIGS. 8-10, 13, and 14. The catheter 12 includes a pusher 30 including a distal portion 32. The pusher 30 is configured to be advanced and retracted through the deflectable element 16. The catheter 12 also includes a distal connector 34 connected to a distal portion 32 of the pusher 30. A proximal end of the flexible polymer circuit strip 24 is connected to the proximal connector 20, and a distal end of the flexible polymer circuit strip 24 is connected to the distal connector 34, with the flexible polymer circuit strip 24 disposed circumferentially around the distal portion 32 of the pusher 30. The flexible polymer circuit strip 24 is configured to bow radially outward when the pusher 30 is retracted to expand the expandable assembly from a collapsed configuration to an expanded configuration, as will be described in more detail with reference to Figures 7A-7B.

[0048] In some embodiments, the catheter 12 includes a distal electrode 36 disposed at the distal tip of the catheter 12 between the distal ends of the flexible polymer circuit strip 24. In other embodiments, the catheter 12 includes a nose cap (not shown) disposed within the distal coupling 34 in place of the distal electrode 36.

[0049] The catheter 12 includes surface-mountable electrodes 38 electrically connected to respective ones of the flexible polymer circuit strips 24. In some embodiments, one surface-mountable electrode 38 is disposed on each flexible polymer circuit strip 24. The surface-mountable electrodes 38 are electrically connected to the flexible polymer circuit strips 24 via contact pads 28, as will be described in more detail with reference to FIG.

[0050] The surface-mountable electrodes 38 may be connected at the same location on each flexible polymer circuit strip 24, or may be connected in a staggered arrangement with alternating surface-mountable electrodes 38 disposed more proximally than other surface-mountable electrodes 38 so that the expandable assembly 22 can be efficiently compressed when retracted during insertion into and removal from the patient's body part 14.

[0051] In some embodiments, the surface-mountable electrode 38 may be connected to any suitable basket catheter having elements different from those of the catheter 12 .

[0052] The medical system 10 includes an ablation power generator 40 configured to connect to the catheter 12. The ablation power generator 40 may be housed within a console 42. The ablation power generator 40 is configured to apply an electrical signal to one or more of the surface-mountable electrodes 38 to ablate tissue at the body region 14. In some embodiments, the ablation power generator 40 is configured to apply an electrical signal between some of the surface-mountable electrodes 38 to ablate tissue (using RF or IRE ablation). In some embodiments, the ablation power generator 40 is configured to apply an electrical signal between one or more of the surface-mountable electrodes 38 and the distal electrode 36 to ablate tissue at the body region 14 (using RF or IRE ablation).

[0053] The medical system 10 includes a processor 44 configured to execute a mapping module 46 configured to receive electrical signals from at least some of the strip electrodes 26 of the flexible polymer circuit strip 24 and to generate an electroanatomical map 48 in response to the received electrical signals.

[0054] In practice, some or all of the functions of processor 44 may be combined into a single physical component, or alternatively, may be embodied using multiple physical components. These physical components may comprise hardwired or programmable devices, or a combination of the two. In some embodiments, at least some of the functions of processor 44 may be performed by a programmable processor under the control of suitable software. This software may be downloaded to the device in electronic form, for example, over a network. Alternatively or additionally, this software may be stored on a tangible, non-transitory computer-readable medium, such as optical, magnetic, or electronic memory.

[0055] The medical system 10 may include other modules and elements not shown for simplicity, such as an electrocardiogram module, a display screen, and user input devices (e.g., a keyboard and mouse), by way of example only.

[0056] Reference is now made to Figure 2, which is a schematic diagram of the catheter 12 of the system 10 of Figure 1. Figure 2 shows in greater detail the proximal connector 20, the distal connector 34, the flexible polymer circuit strip 24 (only some of which are labeled for simplicity), the pusher 30, and the surface-mountable electrodes 38 (only some of which are labeled for simplicity).

[0057] The inner diameter of the pusher 30 is sized to accommodate a wire. The pusher 30 may be formed from any suitable material, such as, but not limited to, polyimide with or without braid, polyether ether ketone (PEEK) with or without braid, or polyamide with or without braid. The distal link 34 and the proximal link 20 may be formed from any suitable material, such as, but not limited to, polycarbonate with or without glass filler, PEEK with or without glass filler, or PEI with or without glass filler.

[0058] The catheter 12 includes elongated elastic support elements 50 (also referred to herein as elastic substrates) connected along the length of each of the flexible polymer circuit strips 24 (only some are labeled for simplicity), which provide the shape of the expandable assembly 22 in its expanded configuration. The elongated elastic support elements 50 may comprise any suitable material, such as, but not limited to, nitinol and / or polyetherimide (PEI). The elongated elastic support elements 50 extend from the proximal connector 20 along the inner surface of each flexible polymer circuit strip 24 until just before the flexible polymer circuit strip 24 enters the distal connector 34, as described in more detail with reference to FIGS. 4A-4C , allowing the flexible polymer circuit strip 24 to flex sufficiently at that point. The elongated elastic support elements 50 may have any suitable thickness, for example, in the range of approximately 0.025 mm to 0.25 mm.

[0059] Reference is now made to Figure 3, which is a partially exploded view of the catheter 12 of Figure 2. Figure 3 shows the catheter 12 with the distal electrode 36 (or nose piece) and the proximal connector 20 removed to show how the flexible polymer circuit strip 24 is connected to the distal connector 34 and the proximal connector 20. The proximal end of the flexible polymer circuit strip 24 is connected to the inner surface of the proximal connector 20 and is disposed circumferentially around the inner surface of the proximal connector 20. The distal end of the flexible polymer circuit strip 24 is connected to the inner surface of the distal connector 34 and is disposed circumferentially around the inner surface of the distal connector 34. The flexible polymer circuit strip 24 may be connected to the proximal connector 20 and the distal connector 34 using any suitable method, for example, using an adhesive (e.g., epoxy) and / or using a pressure fit. The distal end of the flexible polymer circuit strip 24 is generally bent over and connected to the distal end of the distal connector 34, allowing the flexible polymer circuit strip 24 to bend approximately 90 degrees to form a flat nose catheter. In some embodiments, the distal ends of the flexible polymer circuit strip 24 may be connected to the outer surface of the distal connector 34 or may be connected together without the use of a distal connector.

[0060] Reference is now made to Figure 4A, which is a schematic illustration of the distal end of the catheter 12 of Figure 2 without the distal electrode 36. Reference is also now made to Figures 4B-4C, which are schematic illustrations of the distal end of one of the flexible polymer circuit strips 24 of the catheter 12 of Figure 2. Figure 4A shows that the distal end of the flexible polymer circuit strip 24 is bent into the distal connector 34. In some embodiments, the distal end of the flexible polymer circuit strip 24 is tapered so that the flexible polymer circuit strip 24 fits into the distal connector 34.

[0061] As previously mentioned, the flexible polymer circuit strips 24 are supported using elongated, resilient support elements 50 that extend from the proximal end of the flexible polymer circuit strips 24 to the hinge sections 52 of each flexible polymer circuit strip 24. The hinge sections 52 may be reinforced using any suitable material. In some embodiments, the hinge sections 52 are reinforced using at least one fiber, such as thread 54 (FIG. 4B), that runs between the flexible polymer circuit strips 24 and the elongated, resilient support elements 50 to the distal end of the flexible polymer circuit strips 24. The thread 54 may include any one or more of an ultra-high molecular weight polyethylene thread or a thread spun from a liquid crystal polymer. The thread 54 may be of any suitable linear density, for example, in the range of approximately 25 denier to 250 denier. The flexible polymer circuit strip 24, elongated elastic support element 50, and thread 54 may be attached together using any suitable method, for example, an adhesive such as epoxy, and may be covered with a suitable covering 56 (FIGS. 4B and 4C), for example, thermoplastic polyethylene terephthalate (PET) shrink tubing. Windows are opened in covering 56 to expose strip electrodes 26 and contact pads 28 (FIG. 1).

[0062] Also, in FIG. 4B, it can be seen that hinge section 52 is much thinner (having a thickness "t") than the region containing elongated resilient support element 50. Hinge section 52 may have any suitable thickness, for example, within a range of approximately 10 to 140 micrometers. Hinge section 52 has portion 52A, portion 52B, and end portion 52C. Portion 52A tapers from a width w1 (FIG. 4A) to a smaller width w2 (FIG. 4A). Portion 52B tapers from a width w2 to a smaller final width w3 (FIG. 4A) at end portion 52C. Width w1 is approximately twice width w3. End portion 52C has a length L of approximately 3 mm, ensuring that the electrode can be retained within connector 34 without separation.

[0063] Reference is now made to Figure 5, a cross-sectional view taken through line AA in Figure 1. Figure 5 shows how the distal end of the flexible polymer circuit strip 24 is connected to the inner surface of the distal connector 34. A position sensor 58 (such as a magnetic position sensor) is optionally disposed within the distal connector 34. The distal electrode 36 is inserted within the distal connector 34 between the flexible polymer circuit strip 24 and the position sensor 58. Figure 5 also shows how the distal end of the pusher 30 is connected to the proximal end of the distal connector 34.

[0064] Reference is now made to Figure 6, a cross-sectional view through line BB of Figure 1. Figure 6 shows how the proximal end of the flexible polymer circuit strip 24 is connected to the inner surface of the proximal connector 20. Figure 6 also shows that the proximal connector 20 is connected around the outer surface of the deflectable element 16, which includes a lumen 60 for carrying wires and irrigation tubing, for example, from the distal end to the proximal end of the catheter 12. The flexible polymer circuit strip 24 may additionally be held in place using a retaining ring 62. Figure 6 also shows a pusher 30 extending from one of the lumens 60 of the deflectable element 16 into the expandable assembly 22.

[0065] Reference is now made to FIGS. 7A-7B, which are schematic diagrams showing the catheter 12 of FIG. 1 in the deployed and folded configurations, respectively. The flexible polymer circuit strip 24 is configured to bend radially outward when the pusher 30 is retracted to expand the expandable assembly 22 from the folded configuration to the expanded configuration. The folded configuration of the expandable assembly 22 represents the unstressed form of the flexible polymer circuit strip 24, which is given its shape using the elongated, resilient support elements 50 (FIGS. 4A-4C). In some embodiments, the unstressed form of the expandable assembly 22 is the expanded configuration. In some embodiments, the expandable assembly 22 collapses when retracted into a sheath (not shown) without the need for a pusher or similar element.

[0066] In some embodiments, the flexible polymer circuit strip 24 is formed as a flat strip. The distal end of the flexible polymer circuit strip 24 is connected to the inner surface of the distal connector 34, and the proximal end of the flexible polymer circuit strip 24 is then connected to the proximal connector 20, such that in the collapsed configuration, the angle between the tangent to the distal end of the flexible polymer circuit strip 24 and the axis of the pusher 30 is close to 180 degrees, while in the expanded configuration, the angle between the tangent to the distal end of the flexible polymer circuit strip 24 and the axis is approximately 90 degrees. Thus, in operation (when the flexible polymer circuit strip 24 is connected to the distal electrode 36 and the proximal connector 20), the hinge sections 52 are configured to provide a maximum angular range of movement of the flexible polymer circuit strip 24 of approximately 90 degrees, and typically greater than 80 degrees. However, the hinge sections 52 can bend more than 180 degrees.

[0067] Reference is now made to FIG. 8, which is a schematic diagram of one of the flexible polymer circuit strips 24 of the catheter 12 of FIG. 2. The flexible polymer circuit strip 24 shows strip electrodes 26 and contact pads 28. The contact pads 28 are typically formed in the same manner as the strip electrodes 26, except that the contact pads 28 may be longer than each strip electrode 26. In some embodiments, the contact pads 28 may be the same size as the strip electrodes 26. FIG. 8 also shows the hinge section 52 and elongated resilient support element 50 on the underside of the flexible polymer circuit strip 24. The flexible polymer circuit strip 24 also includes a contact array 64 for connecting the strip electrodes 26 and contact pads 28 to wires that extend from the deflectable element 16 (FIG. 1) to the proximal end of the catheter 12.

[0068] Reference is now made to Figures 9 and 10, which are schematic diagrams of one of the flexible polymer circuit strips 24 of the catheter 12 of Figure 2, showing a circuit trace 66. The flexible polymer circuit strip 24 in Figures 9 and 10 is shown in a semi-transparent format, allowing visualization of the different layers of the flexible polymer circuit strip 24. The flexible polymer circuit strip 24 is generally formed from multiple layers, including a lower layer and an upper layer. The lower layer of the flexible polymer circuit strip 24 includes circuit traces 66 that connect the strip electrodes 26 and contact pads 28 to the contact array 64. The upper layer includes the strip electrodes 26 and contact pads 28. The circuit traces 66 on the lower layer are connected to the strip electrodes 26 and contact pads 28 on the upper layer using vias (not shown). The circuit traces 66 to the contact pads 28 may be wider than the other circuit traces 66 and may be spaced further apart from the other circuit traces 66 to ensure proper insulation. The circuit traces 66 of the strip electrodes 26 may be approximately 0.005 mm to 0.1 mm wide (e.g., 0.025 mm) and spaced apart from one another from approximately 0.005 mm to 0.1 mm (e.g., 0.025 mm), while the traces 66 of the contact pads 28 may be approximately 0.025 mm to 0.25 mm wide (e.g., 0.125 mm wide) and spaced apart from one another from approximately 0.010 mm to 0.125 mm (e.g., 0.050 mm). The thickness of the traces 66 may be approximately 0.005 mm to 0.100 mm (e.g., 0.010 mm). In some embodiments, the circuit traces 66 may have the same width and spacing. The flexible polymer circuit strips 24 may be constructed of any suitable material. In some embodiments, each of the flexible polymer circuit strips 24 comprises a strip of polyimide. Circuit traces 66 are disposed on the back surface of the polyimide strip, and strip electrodes 26 and contact pads 28 are disposed on the front surface of the polyimide strip.

[0069] The flexible polymer circuit strip 24 may have any suitable dimensions. For example, the length of the flexible polymer circuit strip 24 may range from 10 mm to 60 mm, such as 30 mm, the width of the flexible polymer circuit strip 24 may range from about 0.25 mm to 3 mm, such as 0.72 mm, and the thickness of the flexible polymer circuit strip 24 may range from about 0.005 mm to 0.14 mm.

[0070] Reference is now made to FIG. 11 , which is a schematic diagram of the flexible polymer circuit strip 24 of FIG. 8 having electrodes 26 (e.g., mapping, recording, or diagnostic electrodes) (only some of which are labeled for simplicity) on which one of the surface-mountable electrodes 38 is attached. The electrodes 26 are generally used to record electrical signals (e.g., electrocardiogram or intracardiac electrogram signals) generated by biological tissue (e.g., cardiac tissue). Each electrode 26 has an exposed surface area A1. Each electrode 26 is typically a planar electrode. The surface-mounted electrode 38 may be used for ablation, for example, by delivering a DC or AC signal through the electrode 38. The electrode 38 has an exposed surface area A2 at least three times the exposed area A1 of each mapping electrode 26. In some embodiments, the exposed surface area A1 is from about 0.08 mm to about 1 mm square. The surface-mountable electrode 38 may be formed as a single element that is slid over the flexible polymer circuit strip 24 and the elongated, resilient support element 50. In some embodiments, the surface-mountable electrode 38 may be formed from two halves that are connected together around the strip 24 and the elongated, resilient support element 50. In yet other embodiments, the surface-mountable electrode 38 may be formed as a band that is wrapped around the flexible polymer circuit strip 24 and the elongated, resilient support element 50. The surface-mountable electrode 38 may be formed from any suitable material, for example, but not limited to, gold, a gold alloy, platinum, a platinum alloy, palladium, or a palladium alloy.

[0071] Reference is now made to FIG. 12, which is a more detailed view of the surface-mountable electrode 38 of FIG. 11. The surface-mountable electrode 38 is shown mounted on the contact pad 28. The surface-mountable electrode 38 is electrically connected to the contact pad 28 using two conductive retainers 68 (e.g., using solder, conductive epoxy, resistance welding, laser welding, or any other suitable method). The surface-mountable electrode 38 is further secured to the flexible polymer circuit strip 24 (and / or the elongated resilient support element 50 and / or the contact pad 28) using an adhesive 70, such as polyurethane glue or epoxy. The adhesive 70 may be applied such that the contact pad 28 is electrically isolated from the environment surrounding the catheter 12.

[0072] Reference is now made to FIG. 13, a cross-sectional view taken along line AA in FIG. 12. FIG. 13 shows that the surface-mountable electrode 38 extends above the contact pad 28 and below the elongated, resilient support element 50. The surface-mountable electrode 38 is formed as an elongated member having a semi-cylindrical cross-section as shown in FIG. 13. FIG. 13 also shows two layers of the flexible polymer circuit strip 24: a layer 72 (shown in each of FIGS. 9 and 10) containing the circuit traces 66, and a layer 74 (shown in FIG. 10) containing the contact pad 28 and strip electrode 26. The contact pad 28 shown in FIG. 13 is wider than the surface-mountable electrode 38. In some embodiments, the contact pad 28 may be narrower than the surface-mountable electrode 38 or may be the same width. The surface-mountable electrode 38 is electrically connected to the contact pad 28 using at least one conductive retainer 68. In some embodiments, the proximal and distal ends of the surface-mountable electrode 38 are electrically connected to the contact pad 28 using two respective conductive retainers 68. The proximal and distal ends of the surface-mountable electrode 38 are optionally connected to the flexible polymer circuit strip 24 using an adhesive 70. The adhesive 70 typically covers the remainder of the contact pad 28 not covered by the surface-mountable electrode 38. The adhesive 70 may include, by way of example, a polyurethane adhesive or epoxy. While the bond 68 is typically disposed on the outer surface of the flexible polymer circuit strip 24, the adhesive 70 is generally disposed around the flexible polymer circuit strip 24 and the elongated, resilient support element 50 to secure the surface-mountable electrode 38 to the flexible polymer circuit strip 24 and the elongated, resilient support element 50 and to prevent liquids from contacting the contact pad 28 during use of the catheter 12.

[0073] Reference is now made to Figure 14, a cross-sectional view through line BB of Figure 12. Figure 14 shows that the surface-mountable electrodes 38 extend around the flexible polymer circuit strip 24 and the elongated, resilient support element 50. Figure 14 also shows a thread 54 (or at least one fiber) sandwiched between the flexible polymer circuit strip 24 and the elongated, resilient support element 50. A covering 56 (e.g., shrink tubing) is shown surrounding the elongated, resilient support element 50 and partially surrounding the flexible polymer circuit strip 24, with a window opened in the covering 56 to expose the contact pads 28. 14 is a one-piece hollow electrode (i.e., an ablation electrode with a hollow portion extending therethrough) that is slid over the combination of the flexible polymer circuit strip 24 and the elongated elastic support element 50, allowing the flexible polymer circuit strip 24, thread 54 (or at least one fiber), and elongated elastic support element 50 to extend through the hollow portion. As previously mentioned, the surface-mountable electrode 38 may be formed from two halves connected together around the strip 24. In yet other embodiments, the surface-mountable electrode 38 may be formed as a band wrapped around the flexible polymer circuit strip 24.

[0074] Reference is now made to Figure 15, which is a flow chart 80 including steps in a method of manufacturing the catheter 12 of Figure 2. Reference is also made to Figure 1.

[0075] The method includes forming each flexible polymer circuit strip 24 from multiple layers (block 82), with layer 72 (FIG. 13) including the circuit traces 66 (FIGS. 9 and 10) and layer 74 (FIG. 13) including the strip electrodes 26 and respective contact pads 28.

[0076] The method includes forming or providing (block 84) a catheter 12 including an elongate deflectable element 16, a proximal connector 20 connected to a distal end 18 of the deflectable element 16, a distal connector 34, a distal electrode 36, a pusher 30, and an expandable assembly 22. The expandable assembly 22 includes flexible polymer circuit strips 24. Each flexible polymer circuit strip 24 includes a respective strip electrode 26 and a respective contact pad 28 disposed thereon. The proximal and distal ends of the flexible polymer circuit strips 24 are connected to the proximal and distal connectors 20 and 34, respectively, and are disposed circumferentially around the proximal and distal connectors 20 and 34. A distal electrode 36 is disposed at the distal tip of the catheter 12 between the distal ends of the flexible polymer circuit strips 24. Pusher 30 is configured to advance and retract through deflectable element 16. A distal portion of pusher 30 is connected to distal connector 34. Flexible polymer circuit strip 24 is disposed circumferentially around the distal portion of pusher 30. Flexible polymer circuit strip 24 is configured to bend radially outward when pusher 30 is retracted to expand expandable assembly 22 from the collapsed configuration to the expanded configuration.

[0077] The method also includes connecting (block 86) the surface-mountable electrodes 38 to respective ones of the flexible polymer circuit strips 24. In some embodiments, the method includes connecting the surface-mountable electrodes 38 to respective ones of the flexible polymer circuit strips 24 in a staggered arrangement, with every other one of the surface-mountable electrodes 38 disposed more proximally than the other one of the surface-mountable electrodes 38. The step of block 86 may include the substeps of blocks 88 and 90, as follows:

[0078] The method may also include electrically connecting the surface-mountable electrodes 38 to respective ones of the flexible polymer circuit strips 24 (block 88), such that each surface-mountable electrode 38 is electrically connected to a respective contact pad 28 of a respective one of the flexible polymer circuit strips 24 using at least one conductive retainer 68 ( FIG. 13 ), for example, using solder, conductive epoxy, resistance welding, laser welding, or any other suitable method. In some embodiments, the method includes electrically connecting the proximal and distal ends of each surface-mountable electrode 38 to a respective contact pad 28 of a respective flexible polymer circuit strip 24 using two respective conductive retainers 68.

[0079] The method may also include connecting the proximal and distal ends of each surface-mountable electrode 38 to a respective flexible polymer circuit strip 24 using adhesive 70 (block 90).

[0080] Reference is now made to Figure 16, which is a schematic illustration of an energized ablation electrode 92 for use with the catheter 12 of Figure 2. Reference is now also made to Figure 17, which is a cross-sectional view of the energized ablation electrode 92 through line AA of Figure 16, with the energized ablation electrode 92 disposed on one of the flexible polymer circuit strips 24.

[0081] The energized ablation electrode 92 is a surface-mountable electrode that can replace one or more of the surface-mountable electrodes 38. The energized ablation electrode 92 is fabricated from a biocompatible, electrically conductive material and has an electrode lumen 94 therethrough. The energized ablation electrode 92 has an outer surface 96 and an inner surface 98 defined by the lumen 94.

[0082] Each of the flexible polymer circuit strips 24 has a respective outer surface 100. Each biased ablation electrode 92 includes a conductive material biased toward the respective outer surface 100 of the respective flexible polymer circuit strip 24.

[0083] In some embodiments, for a given biased ablation electrode 92 mated to a given flexible polymer circuit strip 24, the given flexible polymer circuit strip 24 is planar at the given electrode 92, and this planar surface divides the given electrode 92 asymmetrically, such that there is more conductive material on the outer side (of the plane) than on the inner side. In these embodiments, the electrode 92 (i.e., when attached to the flexible polymer circuit strip 24) is biased to the outer side of the flexible polymer circuit strip 24 due to the greater surface area of ​​the given electrode 92 on the outer side compared to the surface area of ​​the given electrode 92 on the inner side.

[0084] Examples of suitable materials for forming the electrodes 92 include gold, platinum, and palladium (and their respective alloys). These materials also have very high thermal conductivity, which allows the minimal heat generated on the tissue (i.e., due to the ablation energy delivered to the tissue) to be conducted through the electrode to the backside of the electrode (i.e., the portion of the electrode on the interior side of the flexible polymer circuit strip 24) and then to the heart's blood pool.

[0085] By biasing the electrode 92 toward the outer surface 100, the electrode 92 delivers more ablation energy from the outer portion of the electrode 92 (i.e., significantly more ablation energy than is delivered from the portion of the electrode on the inner side of the flexible polymer circuit strip 24). The configurations described hereinabove can also allow heat to be transferred from the tissue (i.e., during an ablation procedure) to the portion of the electrode on the inner side of the flexible polymer circuit strip 24, and the electrode 92 can be cooled by directing irrigation fluid, for example, via a spray port (not shown), at the blood pool and / or the portion of the electrode 92 on the inner side of the flexible polymer circuit strip 24.

[0086] The energized ablation electrode 92 can be formed using any suitable method, for example, by extruding a tube of non-radially symmetric conductive material. For example, the tube may have a height of 0.04 inches (±0.003 inches) and a width of 0.048 inches (±0.003 inches), the lumen may have a height of 0.017 inches (±0.001 inches) and a width of 0.032 inches (±0.002 inches), the thickness of the conductive material below the lumen may be 0.003 inches (±0.001 inches), and the thickness of the conductive material above the lumen may be approximately 0.02 inches. During the manufacturing process, a cutting tool may be used to cut multiple electrodes 92 from the tube. In some embodiments, each electrode may have a length of approximately 0.08 inches. A manufacturer may use a cutting tool, such as an electrical discharge machining (EDM) wire, to create the electrodes from the tube.

[0087] The manufacturing process can create sharp edges on the electrode 92. When the catheter 12 is used to perform a high-energy ablation procedure, such as IRE ablation, the application of high ablation energy to the electrode 92 can result in arcing from the sharp edges. In a smoothing process, the manufacturer smooths the edges on the manufactured electrode 92. Examples of smoothing processes that the manufacturer can use include, but are not limited to, tumbling / lubricating and barreling.

[0088] As used herein, the term "about" or "approximately" with respect to any numerical value or range of values ​​indicates a suitable dimensional tolerance that enables a portion of a component or a collection of components to function for its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value; for example, "about 90%" may refer to a range of values ​​of 72% to 108%.

[0089] Various features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

[0090] The above-described embodiments are cited by way of example, and the present invention is not limited to what has been particularly shown and described in the foregoing specification. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described in the foregoing specification, as well as variations and modifications thereof not disclosed in the prior art that would occur to one skilled in the art upon reading the foregoing description.

[0091] [Embodiment] (1) A medical system including a catheter configured to be inserted into a body part of a living subject, the catheter comprising: an elongated deflectable element including a distal end; a proximal connector connected to the distal end; an expandable assembly including a plurality of flexible polymer circuit strips, each including a plurality of strip electrodes and respective contact pads disposed thereon, the flexible polymer circuit strips connected to the proximal connector and having respective proximal ends disposed circumferentially around the proximal connector; a plurality of surface-mountable electrodes electrically connected to respective ones of the flexible polymer circuit strips, each surface-mountable electrode electrically connected to the respective contact pad of each one of the flexible polymer circuit strips using at least one conductive retainer. (2) The system of embodiment 1, wherein each surface-mountable electrode extends around the periphery of a respective one of said flexible polymer circuit strips. (3) an ablation power generator connected to the catheter and configured to apply an electrical signal to at least one of the surface-mountable electrodes to ablate tissue at the body region; The system of embodiment 1, further comprising a mapping module configured to receive electrical signals from the strip electrodes of the flexible polymer circuit strip and generate an electroanatomical map in response to the received electrical signals. (4) The system of embodiment 3, wherein the ablation power generator is configured to apply the electrical signal between ones of the surface-mountable electrodes. (5) the catheter includes a distal connector; the flexible polymer circuit strip is connected to the distal link and has respective distal ends circumferentially disposed around the distal link; the catheter having a distal tip; 2. The system of claim 1, wherein the catheter includes a distal electrode disposed at the distal tip of the catheter between the distal ends of the flexible polymer circuit strip.

[0092] (6) an ablation power generator connected to the catheter and configured to apply an electrical signal between at least one of the surface-mountable electrodes and the distal electrode to ablate tissue at the body region; The system of embodiment 5, further comprising a mapping module configured to receive electrical signals from the strip electrodes of the flexible polymer circuit strip and generate an electroanatomical map in response to the received electrical signals. (7) each surface-mountable electrode includes a proximal end and a distal end; A system as described in embodiment 1, wherein the proximal and distal ends of each surface-mountable electrode are electrically connected to the respective contact pads of the respective flexible polymer circuit strips using two respective conductive retainers. (8) The system of embodiment 7, wherein the proximal and distal ends of each surface-mountable electrode are connected to the respective flexible polymer circuit strips using an adhesive. (9) The system of embodiment 1, wherein each flexible polymer strip includes multiple layers, a first layer of the multiple layers including circuit traces, and a second layer of the multiple layers including the strip electrodes and the respective contact pads. (10) The catheter includes a pusher including a distal portion and configured to advance and retract through the deflectable element; the catheter includes a distal coupling connected to the distal portion of the pusher; the flexible polymer circuit strip is circumferentially disposed around the distal portion of the pusher; the flexible polymer circuit strips having respective distal ends connected to the distal connectors; 2. The system of claim 1, wherein the strip is configured to bend radially outward when the pusher is retracted, expanding the expandable assembly from a collapsed configuration to an expanded configuration.

[0093] (11) The system of embodiment 1, wherein the surface-mountable electrodes are connected to respective ones of the flexible polymer circuit strips in a staggered arrangement in which every other one of the surface-mountable electrodes is disposed more proximally than the other one of the surface-mountable electrodes. (12) The system of claim 1, wherein each of the flexible polymer circuit strips has a respective outer surface, and each of the surface-mountable electrodes comprises a conductive material biased toward the respective outer surface of each of the flexible polymer circuit strips. (13) A method for manufacturing a catheter, comprising: providing a catheter including an elongated deflectable element, a proximal connector connected to a distal end of the elongated deflectable element, and an expandable assembly including a plurality of flexible polymer circuit strips, each including a plurality of strip electrodes and respective contact pads disposed thereon, the flexible polymer circuit strips connected to the proximal connector and having respective proximal ends disposed circumferentially around the proximal connector; electrically connecting a plurality of surface-mountable electrodes to respective ones of the flexible polymer circuit strips such that each surface-mountable electrode is electrically connected to the respective contact pad of each one of the flexible polymer circuit strips using at least one conductive retainer. 14. The method of claim 13, wherein each surface-mountable electrode extends around the periphery of a respective one of the flexible polymer circuit strips. (15) The catheter includes a distal connector; the flexible polymer circuit strip is connected to the distal link and has respective distal ends circumferentially disposed around the distal link; the catheter having a distal tip; 14. The method of claim 13, wherein the catheter comprises a distal electrode disposed at the distal tip of the catheter between the distal ends of the flexible polymer circuit strip.

[0094] (16) The method of embodiment 13, wherein the electrically connecting includes electrically connecting the proximal and distal ends of each surface-mountable electrode to the respective contact pads of the respective flexible polymer circuit strip using two respective conductive retainers. (17) The method of claim 16, further comprising connecting the proximal end and the distal end of each surface-mountable electrode to the respective flexible polymer circuit strip using an adhesive. (18) The method of embodiment 13, further comprising forming each flexible polymer circuit strip from a plurality of layers, a first layer of the plurality of layers comprising circuit traces and a second layer of the plurality of layers comprising the strip electrodes and the respective contact pads. (19) The catheter includes a pusher including a distal portion and configured to advance and retract through the deflectable element; the catheter includes a distal coupling connected to the distal portion of the pusher; the flexible polymer circuit strip is circumferentially disposed around the distal portion of the pusher; the flexible polymer circuit strips having respective distal ends connected to the distal connectors; 14. The method of claim 13, wherein the strip is configured to bow radially outward when the pusher is retracted, expanding the expandable assembly from a collapsed configuration to an expanded configuration. (20) The method of claim 13, further comprising connecting the surface-mountable electrodes to respective ones of the flexible polymer circuit strips in a staggered arrangement in which every other one of the surface-mountable electrodes is disposed more proximally than the other one of the surface-mountable electrodes.

[0095] (21) An electrophysiological flexible circuit device, comprising: an elastic substrate extending from a first substrate end to a second substrate end; a flexible circuit strip extending from a first strip end to a second strip end, the flexible circuit strip being coupled to the elastic substrate and having conductive contact pads disposed on the flexible circuit strip; a plurality of recording electrodes disposed on the flexible circuit strip, each recording electrode configured to record electrical signals from biological tissue; at least one fiber disposed between the elastic substrate and the flexible circuit strip; an ablation electrode having a hollow portion extending therethrough and allowing the flexible circuit strip, the at least one fiber, and the elastic substrate to extend therethrough, the ablation electrode having at least one conductive retainer electrically connecting the ablation electrode to the conductive contact pad. (22) The device of embodiment 21, further comprising an adhesive that attaches the ablation electrodes to any one or more of the flexible circuit strip, the elastic substrate, and the conductive contact pads. (23) The device described in embodiment 21, wherein each of the recording electrodes includes a first exposed surface area and each ablation electrode includes a second exposed surface area that is at least three times the first exposed surface area. (24) The device of claim 21, wherein the first strip end includes a hinge and a first portion, a second portion, and a third portion, the first portion having a first width that tapers to a second width, and the second portion tapers from the second width to a final width at the third portion of the first strip end. 25. The device of claim 21, wherein the at least one fiber comprises a yarn.

[0096] (26) The device of embodiment 21, wherein each recording electrode comprises a planar electrode. (27) The device described in embodiment 21, wherein the ablation electrode comprises an elongated member having a semi-cylindrical cross section.

Claims

1. 1. A medical system including a catheter configured to be inserted into a body site of a living subject, the catheter comprising: an elongated deflectable element including a distal end; a proximal connector connected to the distal end; an expandable assembly including a plurality of flexible polymer circuit strips, each including a plurality of strip electrodes and respective contact pads disposed thereon, the plurality of flexible polymer circuit strips being connected to the proximal connector and having respective proximal ends disposed circumferentially around the proximal connector; a plurality of surface-mountable electrodes electrically connected to respective ones of the plurality of flexible polymer circuit strips, each surface-mountable electrode electrically connected to a respective one of the contact pads of the respective ones of the plurality of flexible polymer circuit strips using at least one conductive retainer; at least one surface-mountable electrode of the plurality of surface-mountable electrodes has a lumen, the lumen extending through the at least one surface-mountable electrode and allowing the flexible polymer circuit strip to extend through the lumen; the at least one surface-mountable electrode is asymmetrically divided by the flexible polymer circuit strip extending through the lumen; a surface of the at least one surface-mountable electrode on an exterior side of the flexible polymer circuit strip having a curved shape of a semi-cylindrical, and a surface area of ​​the at least one surface-mountable electrode on the exterior side of the flexible polymer circuit strip that is greater than a surface area of ​​the at least one surface-mountable electrode on an interior side of the flexible polymer circuit strip.

2. The medical system of claim 1 , wherein each surface-mountable electrode extends around a respective one of the flexible polymer circuit strips.

3. an ablation power generator connected to the catheter and configured to apply an electrical signal to at least one of the plurality of surface-mountable electrodes to ablate tissue at the body region; 10. The medical system of claim 1, further comprising: a mapping module configured to receive electrical signals from ones of the plurality of strip electrodes of the plurality of flexible polymer circuit strips and to generate an electroanatomical map in response to the received electrical signals.

4. The medical system of claim 3 , wherein the ablation power generator is configured to apply the electrical signal between ones of the plurality of surface-mountable electrodes.

5. the catheter includes a distal connector; the plurality of flexible polymer circuit strips are connected to the distal connector and have respective distal ends circumferentially disposed around the distal connector; the catheter having a distal tip; The medical system of claim 1 , wherein the catheter includes a distal electrode disposed at the distal tip of the catheter between the distal ends of the plurality of flexible polymer circuit strips.

6. an ablation power generator connected to the catheter and configured to apply an electrical signal between at least one of the plurality of surface-mountable electrodes and the distal electrode to ablate tissue at the body region; 6. The medical system of claim 5, further comprising: a mapping module configured to receive electrical signals from ones of the plurality of strip electrodes of the plurality of flexible polymer circuit strips and to generate an electroanatomical map in response to the received electrical signals.

7. each surface-mountable electrode including a proximal end and a distal end; 10. The medical system of claim 1, wherein the proximal and distal ends of each surface-mountable electrode are electrically connected to the respective contact pads of the respective flexible polymer circuit strip using two respective conductive retainers.

8. 8. The medical system of claim 7, wherein the proximal and distal ends of each surface-mountable electrode are connected to the respective flexible polymer circuit strip using an adhesive.

9. 10. The medical system of claim 1, wherein each flexible polymer strip includes multiple layers, a first layer of the multiple layers including circuit traces, and a second layer of the multiple layers including the multiple strip electrodes and respective contact pads.

10. the catheter includes a pusher including a distal portion and configured to advance and retract through the deflectable element; the catheter includes a distal coupling connected to the distal portion of the pusher; the plurality of flexible polymer circuit strips are circumferentially disposed around the distal portion of the pusher; the plurality of flexible polymer circuit strips having respective distal ends connected to the distal connector; 10. The medical system of claim 1, wherein the plurality of flexible polymer circuit strips are configured to bow radially outward when the pusher is retracted, expanding the expandable assembly from a collapsed configuration to an expanded configuration.

11. 2. The medical system of claim 1, wherein the plurality of surface-mountable electrodes are connected to respective ones of the plurality of flexible polymer circuit strips in a staggered arrangement with every other one of the plurality of surface-mountable electrodes disposed more proximally than the other one of the plurality of surface-mountable electrodes.

12. 2. The medical system of claim 1, wherein each of the plurality of flexible polymer circuit strips has a respective outer surface, and each of the plurality of surface-mountable electrodes includes a conductive material biased toward the respective outer surface of a respective one of the plurality of flexible polymer circuit strips.

13. 1. A method of manufacturing a catheter, comprising: providing a catheter including an elongated deflectable element, a proximal connector connected to a distal end of the elongated deflectable element, and an expandable assembly including a plurality of flexible polymer circuit strips, each including a plurality of strip electrodes and respective contact pads disposed thereon, the plurality of flexible polymer circuit strips connected to the proximal connector and having respective proximal ends disposed circumferentially around the proximal connector; electrically connecting a plurality of surface-mountable electrodes to respective ones of the plurality of flexible polymer circuit strips such that each surface-mountable electrode is electrically connected to a respective one of the contact pads of a respective one of the plurality of flexible polymer circuit strips using at least one conductive retainer; at least one surface-mountable electrode of the plurality of surface-mountable electrodes has a lumen, the lumen extending through the at least one surface-mountable electrode and allowing the flexible polymer circuit strip to extend through the lumen; the at least one surface-mountable electrode is asymmetrically divided by the flexible polymer circuit strip extending through the lumen; a surface of the at least one surface-mountable electrode on the exterior side of the flexible polymer circuit strip having a curved semi-cylindrical shape, and a surface area of ​​the at least one surface-mountable electrode on the exterior side of the flexible polymer circuit strip that is greater than a surface area of ​​the at least one surface-mountable electrode on the interior side of the flexible polymer circuit strip.

14. The method of claim 13 , wherein each surface-mountable electrode extends around a periphery of a respective one of the flexible polymer circuit strips.

15. the catheter includes a distal connector; the plurality of flexible polymer circuit strips are connected to the distal connector and have respective distal ends circumferentially disposed around the distal connector; the catheter having a distal tip; The method of claim 13 , wherein the catheter includes a distal electrode disposed at the distal tip of the catheter between the distal ends of the plurality of flexible polymer circuit strips.

16. 14. The method of claim 13, wherein said electrically connecting comprises electrically connecting a proximal end and a distal end of each surface-mountable electrode to a respective one of the contact pads of a respective one of the flexible polymer circuit strips using two respective conductive retainers.

17. 17. The method of claim 16, further comprising connecting the proximal end and the distal end of each surface-mountable electrode to the respective flexible polymer circuit strip using an adhesive.

18. 14. The method of claim 13, further comprising forming each flexible polymer circuit strip from a plurality of layers, a first layer of the plurality of layers including circuit traces and a second layer of the plurality of layers including the plurality of strip electrodes and respective contact pads.

19. the catheter includes a pusher including a distal portion and configured to advance and retract through the deflectable element; the catheter includes a distal coupling connected to the distal portion of the pusher; the plurality of flexible polymer circuit strips are circumferentially disposed around the distal portion of the pusher; the plurality of flexible polymer circuit strips having respective distal ends connected to the distal connector; 14. The method of claim 13, wherein the plurality of flexible polymer circuit strips are configured to bow radially outward when the pusher is retracted to expand the expandable assembly from a collapsed configuration to an expanded configuration.

20. 14. The method of claim 13, further comprising connecting the plurality of surface-mountable electrodes to respective ones of the plurality of flexible polymer circuit strips in a staggered arrangement in which every other one of the plurality of surface-mountable electrodes is disposed more proximally than another one of the plurality of surface-mountable electrodes.

21. 1. An electrophysiology flexible circuit device comprising: an elastic substrate extending from a first substrate end to a second substrate end; a flexible circuit strip extending from a first strip end to a second strip end, the flexible circuit strip being coupled to the elastic substrate and having conductive contact pads disposed on the flexible circuit strip; a plurality of recording electrodes disposed on the flexible circuit strip, each recording electrode configured to record electrical signals from biological tissue; at least one fiber disposed between the elastic substrate and the flexible circuit strip; an ablation electrode having a hollow portion extending through the ablation electrode and allowing the flexible circuit strip, the at least one fiber, and the elastic substrate to extend through the hollow portion, the ablation electrode having at least one conductive retainer electrically connecting the ablation electrode to the conductive contact pad; the ablation electrode is asymmetrically divided by the flexible circuit strip extending through the hollow portion; 1. An electrophysiology flexible circuit device, wherein a surface of the ablation electrode on an exterior side of the flexible circuit strip has a semi-cylindrical curved shape, and a surface area of ​​the ablation electrode on the exterior side of the flexible circuit strip is greater than a surface area of ​​the ablation electrode on an interior side of the flexible circuit strip.

22. 22. The electrophysiology flexible circuit device of claim 21, further comprising an adhesive that attaches the ablation electrodes to any one or more of the flexible circuit strip, the elastic substrate, and the conductive contact pads.

23. 22. The electrophysiology flexible circuit device of claim 21, wherein each of the plurality of recording electrodes includes a first exposed surface area and each ablation electrode includes a second exposed surface area that is at least three times the first exposed surface area.

24. 22. The electrophysiology flexible circuit device of claim 21, wherein the first strip end includes a hinge and a first portion, a second portion, and a third portion, the first portion having a first width that tapers to a second width, and the second portion tapers from the second width to a final width at the third portion of the first strip end.

25. 22. The electrophysiological flexible circuit device of claim 21, wherein the at least one fiber comprises a thread.

26. 22. The electrophysiological flexible circuit device of claim 21, wherein each recording electrode comprises a planar electrode.

27. 22. The electrophysiology flexible circuit device of claim 21, wherein the ablation electrodes comprise elongated members having semi-cylindrical cross sections.

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